A large wooden turntable in the shape of a flat disk has a radius of 2.45 m and a total mass of 140 kg . The turntable is initially rotating at 3.20 rad/s about a vertical axis through its center. Suddenly, a 68.5 kg parachutist makes a soft landing on the turntable at a point on its outer edge.

Find the angular speed of the turntable after the parachutist lands.(Assume that you can treat the parachutist as a particle.)

While prepping to start an internship at the local hospital you learn that systemic arteries have diameters greater than 10 mm. You know that blood carries charged particles, and you start to wonder how strong a uniform magnetic field would have to be in order to detect the flow of these charges in the blood with a voltmeter that can measure voltage differences down to a millivolt. You assume that the blood flows at a rate of about 10 cm/s

I was wondering, is there more or less water on the Earth than there used to be a million years ago?

The emissivity of the human skin is 97.0 percent. Use 35.0 °C for the skin temperature and approximate the human body by a rectangular block with a height of 1.57 m, a width of 41.5 cm and a length of 21.0 cm. Calculate the power emitted by the human body.

Fortunately our environment radiates too. The human body absorbs this radiation with an absorbance of 97.0 percent, so we don't lose our internal energy so quickly. How much power do we absorb when we are in a room where the temperature is 22.0 °C?

How much energy does our body lose in one second?

You are testing a new t-shirt cannon. You decide to fire the t-shirts vertically straight up in the air so that you do not have to walk to pick up the launched t-shirts. First, a green t-shirt is launched vertically upwards with a speed of 12 m/s. Exactly 1.0 s later, a blue t-shirt is launched vertically upwards with a speed of 18 m/s. At what time (after the launch of the first green t-shirt) will the two shirts collide, and at what height above the cannon? You may ignore air resistance throughout the problem.

Good old Florida! As an alum of UCF, you also plan to use an off-grid power system. While you absolutely adore four-wheel drive, you bought a plug-in hybrid car, for cost efficiency. Estimate the number of excess solar panels you would need to add to your off-grid power system in order to keep your car charged up without ever burning a drop of gasoline.

4. The SI unit of electric charge is the coulomb, C, is equivalent to the charge on 6.242⨯1018 protons. Express amps and ohms in terms of the base SI units of J, C, and s. Use dimensional analysis and Ohm’s Law to show that volts may be expressed as J/C. (2 points)

Physics Prelab: Magnetism

Watch the video on magnetism. Explain how the “two” right hand rules works –what does each indicate?

How do magnetic fields get their start - what causes magnetic fields?

What is the force a magnetic field exerts on a charged particle?  Write down the equation and explain the direction.

Explain how a solenoid works - how does it produce a magnetic field?

What are the five major types of magnetic materials? Describe each briefly.

6. For ONE day, keep track of all of the electrical devices that you make use of and for how long. (eg. Microwave oven for 3 minutes; hair dryer for 5 minutes; TV for 90 minutes;...) Track only those devices over which you have direct control and don’t bother about things like home heating and refrigerators that are too challenging to track. Using either a published table of common power ratings (cite your source), or information read off of the device itself, work out the electrical energy consumed by each appliance. (Recall that Energy = Power × Time; express time in hours and power in kilowatts to obtain energy in units of kilowatt-hours.) Present a summary of your findings for that one day in table form (include the name of the device, hours used, power rating, and energy consumed). Which device(s) accounts for most of your electricity consumption? Do you think you can realistically reduce your discretionary consumption of electricity? If so, describe how. (NOTE: Devices that are plugged in but “off” like TVs and chargers still consume a small amount of power - so-called “standby” or “phantom” power. Try to include these contributions. A document from a prior year containing more detailed instructions has been placed on Moodle - its first two pages may be useful to you.)

An infinite nonconducting sheet has a surface charge density σ = 8.00 pC/m².

(a) How much work is done by the electric field due to the sheet if a particle of charge q = +1.60 ✕ 10⁻¹⁹ C is moved from the sheet to a point P at distance d = 3.52 cm from the sheet?    

(b) If the electric potential V is defined to be zero on the sheet, what is V at P?

The distance from earth to the center of the galaxy is about 22500 ly (1 ly = 1 light-year = 9.47 ? 10¹⁵ m), as measured by an earth-based observer. A spaceship is to make this journey at a speed of 0.9950c. According to a clock on board the spaceship, how long will it take to make the trip? Express your answer in years (1 yr = 3.16 ? 10⁷ s).

Please be as detailed as possible in your response, thank you!

A solid conducting sphere of radius a carries a net positive charge 2Q. A conducting spherical shell of inner radius b and outer radius c is concentric with the solid sphere and carries a net charge –Q. Let c > b > a.

a) Discuss the distribution of the charges.

b) Calculate the surface charge density on the three surfaces i. radius a ii. radius b iii. radius c.

c) Find the electric field in all the regions. Express this as a function of r measured from the center of the spheres

An elevator accelerates upward at 1 m/s2. When the elevator is moving upward at 2 m/s, a bolt drops from the ceiling which is 2.5 m above the ?oor. Assume that the bolt does not experience air resistance. Calculate how long it takes for the bolt to hit the ?oor, how far it travels, and how fast it is going when it hits the ?oor of the elevator. Solve this problem in two reference frames, one ?xed with respect to the building and one ?xed with respect to the elevator. Only the fall time will be the same for the two reference frames. In this and subsequent problems you solve in dynamics, think about the advantages and disadvantages of various reference frames and clearly state what reference frame you ultimately choose for your solution.

In the time that it takes a whiteboard marker of mass 12 grams to fall 1 meter down to the Earth of mass 6 × 10 kg, 24 (a) how far does the earth move up towards the whiteboard marker? Derive your answer from Newton’s laws, and state when you are using which law. (b) Given that the smallest scale we have measured to date is 0.00000000000000000001 meters = 10 -20 m, can we measure this distance from part (a) yet? (c) Therefore, is part (a) a scientific question? A “scientific question” has to be measurable or falsifiable “in principle” (not necessarily in practice according to current technology).

Bonham the dog stands at the far end of a 14 ft, uniform boat pointing to shore (the drawings below are not exactly to scale). The boat is twice as massive as Bonham. Initially, the dog is 20 ft from shore. Eying his owner on shore, Bonham trots to the front of the boat and stops. Assuming no friction and no water current, and also that he walks the full 14 ft length of the boat (meaning his length is small by comparison), how close is Bonham from shore then?